@phdthesis{Georgiev2021,
  author    = {Georgiev, Kostadin},
  title     = {Sustainable management of naturally disturbed forests},
  doi       = {10.25972/OPUS-24285},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242854},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Owing to climate change, natural forest disturbances and consecutive salvage logging are drastically increasing worldwide, consequently increasing the importance of understanding how these disturbances would affect biodiversity conservation and provision of ecosystem services. In chapter II, I used long-term water monitoring data and mid-term data on α-diversity of twelve species groups to quantify the effects of natural disturbances (windthrow and bark beetle) and salvage logging on concentrations of nitrate and dissolved organic carbon (DOC) in streamwater and α-diversity. I found that natural disturbances led to a temporal increase of nitrate concentrations in streamwater, but these concentrations remained within the health limits recommended by the World Health Organization for drinking water. Salvage logging did not exert any additional impact on nitrate and DOC concentrations, and hence did not affect streamwater quality. Thus, neither natural forest disturbances in watersheds nor associated salvage logging have a harmful effect on the quality of the streamwater used for drinking water. Natural disturbances increased the α-diversity in eight out of twelve species groups. Salvage logging additionally increased the α-diversity of five species groups related to open habitats, but decreased the biodiversity of three deadwood-dependent species groups. In chapter III, I investigated whether salvage logging following natural disturbances (wildfire and windthrow) altered the natural successional trajectories of bird communities. I compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, over a period of 17 years and tested whether bird community dissimilarities changed over time for taxonomic, functional and phylogenetic diversity when rare, common and dominant species were weighted differently. I found that salvage logging led to significantly larger dissimilarities than expected by chance and that these dissimilarities persisted over time for rare, common and dominant species, evolutionary lineages, and for rare functional groups. Dissimilarities were highest for rare, followed by common and dominant species. In chapter IV, I investigated how β-diversity of 13 taxonomic groups would differ in intact, undisturbed forests, disturbed, unlogged forests and salvage-logged forests 11 years after a windthrow and salvage logging. The study suggests that both windthrow and salvage logging drive changes in between-treatment β-diversity, whereas windthrow alone seems to drive changes in within-treatment β-diversity. Over a decade after the windthrow at the studied site, the effect of subsequent salvage logging on within-treatment β-diversity was no longer detectable but the effect on between-treatment β-diversity persisted, with more prominent changes in saproxylic groups and rare species than in non-saproxylic groups or common and dominant species. Based on these results, I suggest that salvage logging needs to be carefully weighed against its long-lasting impact on communities of rare species. Also, setting aside patches of naturally disturbed areas is a valuable management alternative as these patches would enable post-disturbance succession of bird communities in unmanaged patches and would promote the conservation of deadwood-dependent species, without posing health risks to drinking water sources.},
  subject      = {species richness},
  language  = {en}
}
@article{ThornChaoBernhardtRoemermannetal.2020,
  author    = {Thorn, Simon and Chao, Anne and Bernhardt-R{\"o}mermann, Markus and Chen, Yan-Han and Georgiev, Kostadin B. and Heibl, Christoph and M{\"u}ller, J{\"o}rg and Sch{\"a}fer, Hanno and B{\"a}ssler, Claus},
  title     = {Rare species, functional groups, and evolutionary lineages drive successional trajectories in disturbed forests},
  series = {Ecology},
  volume    = {101},
  journal   = {Ecology},
  number    = {3},
  doi       = {10.1002/ecy.2949},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212378},
  pages     = {e02949},
  year      = {2020},
  abstract  = {Following natural disturbances, additional anthropogenic disturbance may alter community recovery by affecting the occurrences of species, functional groups, and evolutionary lineages. However, our understanding of whether rare, common, or dominant species, functional groups, or evolutionary lineages are most strongly affected by an additional disturbance, particularly across multiple taxa, is limited. Here, we used a generalized diversity concept based on Hill numbers to quantify the community differences of vascular plants, bryophytes, lichens, wood-inhabiting fungi, saproxylic beetles, and birds in a storm-disturbed, experimentally salvage logged forest. Communities of all investigated species groups showed dissimilarities between logged and unlogged plots. Most species groups showed no significant changes in dissimilarities between logged and unlogged plots over the first seven years of succession, indicating a lack of community recovery. In general, the dissimilarities of communities were mainly driven by rare species. Convergence of dissimilarities occurred more often than divergence during the early stages of succession for rare species, indicating a major role in driving decreasing taxonomic dissimilarities between logged and unlogged plots over time. Trends in species dissimilarities only partially match the trends in dissimilarities of functional groups and evolutionary lineages, with little significant changes in successional trajectories. Nevertheless, common and dominant species contributed to a convergence of dissimilarities over time in the case of the functional dissimilarities of wood-inhabiting fungi. Our study shows that salvage logging following disturbances can alter successional trajectories in early stages of forest succession following natural disturbances. However, community changes over time may differ remarkably in different taxonomic groups and are best detected based on taxonomic, rather than functional or phylogenetic dissimilarities.},
  language  = {en}
}
@article{GeorgievChaoCastroetal.2020,
  author    = {Georgiev, Kostadin B. and Chao, Anne and Castro, Jorge and Chen, Yan-Han and Choi, Chang-Yong and Fontaine, Joseph B. and Hutto, Richard L. and Lee, Eun-Jae and M{\"u}ller, J{\"o}rg and Rost, Josep and Żmihorski, Michal and Thorn, Simon},
  title     = {Salvage logging changes the taxonomic, phylogenetic and functional successional trajectories of forest bird communities},
  series = {Journal of Applied Ecology},
  volume    = {57},
  journal   = {Journal of Applied Ecology},
  number    = {6},
  doi       = {10.1111/1365-2664.13599},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214887},
  pages     = {1103 -- 1112},
  year      = {2020},
  abstract  = {Salvage logging following natural disturbances may alter the natural successional trajectories of biological communities by affecting the occurrences of species, functional groups and evolutionary lineages. However, few studies have examined whether dissimilarities between bird communities of salvaged and unsalvaged forests are more pronounced for rare species, functional groups and evolutionary lineages than for their more common counterparts. We compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, covering a 17-year period following wildfire or windstorm disturbances and subsequent salvage logging. We tested whether dissimilarities based on non-shared species, functional groups and evolutionary lineages (a) decreased or increased over time and (b) the responses of rare, common and dominant species varied, by using a unified statistical framework based on Hill numbers and null models. We found that dissimilarities between bird communities caused by salvage logging persisted over time for rare, common and dominant species, evolutionary lineages and for rare functional groups. Dissimilarities of common and dominant functional groups increased 14 years post disturbance. Salvage logging led to significantly larger dissimilarities than expected by chance. Functional dissimilarities between salvaged and unsalvaged sites were lower compared to taxonomic and phylogenetic dissimilarities. In general, dissimilarities were highest for rare, followed by common and dominant species. Synthesis and applications. Our research demonstrates that salvage logging did not decrease dissimilarities of bird communities over time and taxonomic, functional and phylogenetic dissimilarities persisted for over a decade. We recommend resource managers and decision makers to reserve portions of disturbed forest to enable unmanaged post-disturbance succession of bird communities, particularly to conserve rare species found in unsalvaged disturbed forests.},
  language  = {en}
}